The human foot takes the brunt of impact of every step experienced by an individual. When a person's foot becomes injured in some way, the foot must be somehow casted or braced in order to prevent movement of an injured area so as to encourage correction of the injury or to prevent movement of an area that has been surgically treated so that the benefits of the surgery will not be undone.
Casts, for example, can be applied to the foot. Traditional casts surround the injured patient's foot and so limit movement of the injured or surgically-treated area. However, traditional casts are fully rigid, preventing movement of the non-injured areas of the foot in addition to the injured or treated areas. Their heaviness and bulk also make mobility more difficult for the patient. Often the cast cannot be removed and reapplied.
Braces, on the other hand, are usually lighter than casts. This allows for more mobility by the patient. However, common braces are also usually not as rigid, which provides less protection to the injured area of the foot or the already-treated area of the foot. In braces that are partially rigid, the foot is prone to movement within the brace so that, again, the injured area of the foot or the already-treated area of the foot is not always as protected or immobilized as it should be. Further, traditional braces are not of a customized shape, but are more of a one-size-fits-all. As such, they are not well suited for use with patients with any but the average shape of foot. Some traditional braces include hinges to allow the foot to move up and down, but not side to side. These braces, while allowing some movement of the patient's foot, do not accommodate the natural tri-planar movement of the foot.